mailman.service failed.

Got an alert that mailman failed. Logged into whm > restart services and got this result, several times: # systemctl status mailman.service ? mailman.service - mailman services Loaded: loaded (/etc/systemd/system/mailman.service; enabled; vendor preset: disabled) Active: failed (Result: exit-code) since Fri 2018-09-21 10:45:11 WIB; 4min 25s ago Process: 26038 ExecStart=/usr/local/cpanel/scripts/restartsrv_mailman --no-verbose --notconfigured-ok (code=exited, status=0/SUCCESS) Main PID: 26044 (code=exited, status=1/FAILURE) Sep 21 10:45:10 whm systemd[1]: Starting mailman services... Sep 21 10:45:10 whm restartsrv_mailman[26038]: Starting Mailman's master qrunner. Sep 21 10:45:10 whm systemd[1]: PID file /usr/local/cpanel/3rdparty/mailman/data/master-qrunner.pid not readable (yet?) after start. Sep 21 10:45:10 whm systemd[1]: Started mailman services. Sep 21 10:45:11 whm systemd[1]: mailman.service: main process exited, code=exited, status=1/FAILURE Sep 21 10:45:11 whm systemd[1]: Unit mailman.service entered failed state. Sep 21 10:45:11 whm systemd[1]: mailman.service failed. Waiting for "mailman" to start "Waiting for mailman,qrunner to shutdown ... not running. "failed. Cpanel::Exception::Services::StartError Service Status Service Error (XID 7ukn7k) The "mailman" service failed to start. Startup Log Sep 21 11:07:51 whm systemd[1]: Starting mailman services... Sep 21 11:07:51 whm restartsrv_mailman[32133]: Starting Mailman's master qrunner. Sep 21 11:07:51 whm systemd[1]: PID file /usr/local/cpanel/3rdparty/mailman/data/master-qrunner.pid not readable (yet?) after start. Sep 21 11:07:52 whm systemd[1]: Started mailman services. Sep 21 11:07:52 whm systemd[1]: mailman.service: main process exited, code=exited, status=1/FAILURE Sep 21 11:07:52 whm systemd[1]: Unit mailman.service entered failed state. Sep 21 11:07:52 whm systemd[1]: mailman.service failed. mailman has failed. Contact your system administrator if the service does not automagically recover. [root@whm ~]#
enabled in WHM > Tweak Settings > Enable Mailman enabled in WHM > Service Manager